Summary

Improvised explosive device (IED) is defined here as an explosive device that is placed or fabricated in an improvised manner; incorporates destructive, lethal, noxious, pyrotechnic, or incendiary chemicals; and is designed to destroy, incapacitate, harass, or distract. IEDs may incorporate military stores, but they are normally devised from nonmilitary components. They are as varied as “command-detonated” pipe bombs, “booby-trapped” military ordnance, and car bombs. They always contain explosive materials, detonators, and triggering mechanisms; they are often cased and may use shrapnel. The term improvised may apply either to the construction of the device or to its use by irregular forces. Thus, a mine produced for regular forces may be considered an IED if it is used by irregular forces, but an unmodified mine placed by regular forces is not considered an IED. Explosive devices designed to disperse chemical, biological, or radiological material are generally not classified as IEDs and were not considered for this study.

THE IED THREAT

Throughout history, and with varying effectiveness, groups have resorted to the use of IEDs to advance a particular cause or wear down an adversary. IEDs are used by terrorists to strike soft targets and by insurgents as weapons against a stronger enemy. They can be made at relatively low cost, are relatively easy to construct and emplace, and can achieve both strategic and tactical results.

The concerted use of IEDs to achieve an adversary’s strategic or tactical goals is referred to as an IED campaign. Two fundamental aspects of an IED campaign are its asymmetry and idiosyncratic nature.1 Overarching the IED campaign is the sociopolitical context of the insurgency or terrorist group that carries it out. The adversary’s objective, beyond casualties, is usually to affect the psychology of the local population or the populations of other engaged nations by creating fear, instability, or discomfort. The adversary expects to move these audiences in ways advantageous to their cause. Counter-IED and counterinsurgency efforts are inexorably linked, and counterinsurgency concepts can be used as tools to defeat an IED campaign.

The ability of the adversary to learn and adapt has been an important characteristic of IED campaigns. The time needed to adapt has typically been shorter than the time needed by counter-IED forces to deploy and implement IED countermeasures. Moreover, IED countermeasures often have the effect of shifting the threat from one device or tactic to another.

In an IED campaign, the adversary must carry out numerous steps before initiating an IED attack. That process includes obtaining funding and bomb materials, recruiting people, constructing the device, selecting the target, delivering the device to its target, carrying out the attack, and disseminating information about the attack for propaganda or other purposes. Together, such steps make up the IED threat chain.

The elements of the threat chain can be grouped into three basic components: organization, resources, and operations. The adversary must have an organization of trusted people with secure communication, connections to outside sources of support, a public interface for recruitment and publicity, and some degree of popular support or tolerance. Destabilization of the organization would inhibit the ability to field an effective IED campaign. Key resources needed to support an IED campaign include people, materiel, money, information, facilities, and access to social networks. For each of those essential resources, there are observables, signatures, and opportunities for interception, tagging, tracking, rigging, or otherwise exploiting the contact to gain access to, or information about, the organization. Operations include items directly associated with the IED device, from weapon manufacture, storage, preparation activities, and the attack itself through postattack evasion. Most of the Department of Defense IED-defeat effort has been devoted to operations, which most resemble traditional military operations.

1

Asymmetry is the absence of a common basis of comparison with respect to a quality or a capability; idiosyncrasy is possession of a peculiar or eccentric pattern.

COUNTERING THE IED THREAT

An ideal approach to defeating the IED threat would include a set of integrated efforts aimed at squeezing the adversary at each stage of the IED threat chain. However, limitations in understanding or in technical capabilities prevent that. The limitations suggest areas of basic research that are relevant to the IED challenge, and those areas are set out below.

Relationships Between the Human Terrain and the IED Threat

The human terrain—the political, social, cultural, and economic environment—is a critical element at all stages of an IED attack, and it probably is also the most complex and the least well understood. Within the social and behavioral sciences, numerous methods can be used in novel counter-IED research. Formal mathematical modeling, statistical or quantitative analysis, and qualitative work, such as case studies and focused historical comparisons, can play an important role. Comparative case studies based on field research could be useful where such work is feasible. Survey research is highly relevant. Red teaming, gaming, and simulations may be useful to enhance prediction. A social-sciences research program aimed at countering IEDs would integrate a variety of behavioral and social-science methods and link social-science knowledge to the methods proposed by science and technology.

Data Acquisition, Data Fusion, and Analysis

There is a need to detect the activities that precede IED use so as to predict events well before an IED detonation. That requires a wide variety of information including data from both human and technical sources, and the systematic inference of actionable knowledge from the fusion of the data. US forces need the capability to extract strategic and tactical actionable intelligence information from massive amounts of diverse, potentially incomplete, and noisy data in a timely and dynamic fashion.

Analytical Techniques for Assessing IED Countermeasures

Analytical methods that quantitatively assess the effectiveness of IED countermeasures are needed. There are some studies about the evaluation of counter-suicide-bombing measures in Israel, and the effectiveness of airline-passenger screening, but to the committee’s knowledge there is nothing in the scientific literature regarding the evaluation of IED countermeasures.

Detection and Disruption Throughout the IED Threat Chain

There are various points in the chain of events leading up to an IED attack at which improved detection and disruption technologies might be usefully applied. For each detection opportunity, there are basic-research issues regarding the particular signatures, methods, and limits of detection. With respect to disruption, technical opportunities exist to improve current approaches or to make them more readily fielded in theater.

Resource Availability and the IED Threat

Available resources—energetic material, initiators, triggering devices, knowledge, finances, and facilities—are critical in determining the type, number, and effectiveness of IED attacks and directly influence the potential for detection and countermeasures. New capabilities and associated basic research are needed to exploit the dependence of the IED threat on those resources.

RESEARCH RECOMMENDATIONS

A major portion of the current IED activities presented to the committee appears to be focused on the operational aspects of the IED threat, the aspects most readily addressed by conventional military means. The recommendations reported here are intended to supplement ongoing work and to provide a broader focus on disrupting the entire IED threat chain. The following recommendations represent research challenges in the five areas discussed above that are compelling based on their potential impact, the potential timeline for their payoff, and the relative level of current effort in these areas.

• Identify the most important and most vulnerable elements in theIED threat chain.

Research should include identifying and analyzing key elements of the threat chain, such as recruitment, availability of technical expertise, diffusion of knowledge, popular support, and the networks and relationships among players. Research should develop a general understanding of how decisions (especially those related to innovations, methods, targets, and timing) are made and how information is communicated in underground organizations, and should examine adversary attitudes toward risk. Due to the role public support, tolerance, or aversion can play in an IED campaign, research should seek to develop better ways of gauging public opinion in different cultural, social, and political contexts and should develop a better understanding of the role of emotion, interpretation, understanding, values, images, and symbols in the IED threat

and investigate potential mechanisms for delegitimizing and devaluing IEDS. Such research should draw on the fields of political science, political economy, sociology, religion, psychology, media and communication, criminology, terrorism studies, anthropology, history, operations research, and international studies. Decision theory, risk, cultural anthropology, and appropriate regional expertise are particularly relevant.

• Use lessons learned from other conflicts and contexts (e.g., lawenforcement) to develop concepts, propositions, and models thatcan be applied more generally.

Analysis of the IED problem should not focus exclusively on current conflicts but should anticipate other potential conflict zones by using the social sciences. Systematic attention should be paid to lessons learned and to their future application. Research can elucidate where and when the threat may migrate and what form it is likely to take. Research subjects include how ideas and tactics are imitated and migrate within and between cultures and societies, the relationship between local insurgents or political factions and transnational terrorist conspiracies, and the role of the media, including the Internet, as a communications tool for terrorists/insurgents. The role of the Internet as a source of information for constructing IEDs and for promoting the cross-national diffusion of ideas and tactics is a particularly important issue that should be examined. Researchers in political science, sociology, psychology, criminology, anthropology, history, media and communication, and international studies can all make valuable contributions.

Research should address the continued development of theory and data to map patterns of social networks, especially during times of conflict and stress. Social-network research can be engaged to understand the conditions and characteristics that could encourage the formation of new networks that support security and stabilization rather than disruption and violence. Research can explore how identities are formed in and sustained by networks, how ethnicity or religion becomes a determinant of identity and may become a catalyst of violence, and how ethnic and sectarian divisions can be overcome. Research should aim to understand the dynamics of societies in the face of rapid and fundamental change. Studies should examine how to undermine terrorism or move to democracy for societies that have a variety of cleavages, values, and cultures. Researchers need to develop a deep understanding of varied cultures and societies and not focus only on those prone to violence; regionally focused

Automated data-collection produces massive amounts of data that may be incomplete and noisy. The timely, accurate use of the data will require the ability to automate data integration and analysis. Research should answer:

How to model intelligence information development and decision making.

How to produce reliable, actionable information from noisy, temporal, and partial data.

How to develop the means to intelligently process data and information.

Research should include development of methods to integrate data from diverse sources into a single inference structure; of open-architecture inference engines that can support new plug-in sensor packages and data sources; and of prototypes for massively scalable data storage and processing architectures. Computer and computational scientists and researchers in data acquisition and analysis, data representation and statistical inference, image interpretation, and sensors can make valuable contributions.

• Develop conceptual bases for identifying both known and potentialclasses of IED threat events.

The ability to identify different types of IED threats in different contexts requires understanding the signatures associated with the threats and the types of data and intelligence information needed to detect those signatures. Such an understanding would provide a basis for developing data collection requirements. This understanding is needed for known classes of IED threats and potential new classes. Research should include developing models of the relationships between threat events and actionable information and defining the requirements for sensor types and ancillary data. Specifying those relationships and requirements will further the development of sensors to acquire the data needed to generate actionable information for a given set of threat events. Computational and behavioral (social, cultural, and geopolitical) scientists and the military,

law-enforcement, and intelligence communities should be involved in this research.

• Understand existing approaches to evaluating IED countermeasures,and establish new metrics and analytical methods for analyzing,assessing, and modeling the operational effectiveness of IEDcountermeasures quantitatively and qualitatively, recognizingthat insurgents/terrorists will change their behavior in response tocountermeasures.

Metrics and analytical methods for assessing IED countermeasures would allow identification of what works, what does not work, and why. Specifically, research should seek to determine trends in overall counter-IED operational effectiveness; determine the relative effectiveness of different counter-IED systems and tactics; discern differences and trends in adversary systems and tactics in different areas; design, test, and evaluate new systems, tactics, and operational concepts; anticipate and pre-empt adversary countermeasures against new systems and tactics; and provide realistic and dynamic simulations. Improved analytical tools would support program planning, operational planning, tactical development, and counter-IED training. Research in statistics, game theory, operations research, military research, and social, cognitive, and economic sciences can make valuable contributions.

• Enhance capabilities for persistent surveillance.

Improvements in persistent surveillance can provide capabilities throughout the IED threat chain. The key research questions can be divided among platform development, sensor development, and image-and data-processing. Another area for study is the control, coordination, and communication of a large number of assets. Persistent surveillance has the potential of generating vast quantities of data. To be useful, improved data storage and transmission, mining, analysis, and processing methods must be developed. There is substantial research in those areas in various agencies, but additional targeted efforts funded by the Department of Defense are encouraged. Researchers in the following fields can contribute: solid-state device research; networking and communication engineering; computer science; mechanical, control, and aeronautical engineering; electrical and optical engineering; and probabilistic inference (for example, computationally limited inference algorithms).

• Determine the fundamental physical limits on the active and passivedetection of arming and firing systems, as well as the physical andchemical limitations for trace and standoff detection.

in the fundamental physical and chemical limits of detection and take into account reasonable extrapolations of existing technology. Quantifying and understanding the variability of background concentrations will help determine the theoretical performance limit of detection systems. Similarly, the physical limits of detecting the electromagnetic signatures of arming and firing systems must be determined in the context of background interferences. Research will be needed in chemical, environmental, and electrical engineering; chemistry and analytical chemistry; applied physics; forensic science; spectroscopy; and optics.

• Develop new methods of remote and standoff detection, andcontinue the development and improvement of sampling-basedmethods for the detection of explosives in the field.

Reliable and rapid explosive detection in a field environment is an unsolved problem. Substantial research and development efforts are under way, but further advances are needed. They may require research in plume and aerosol dynamics; x-ray, microwave, infrared, and terahertz imaging and spectroscopy; neutron, gamma-ray, magnetic resonance, and magnetic-field systems; optical absorption and fluorescence; light detection and ranging (LIDAR), differential-absorption LIDAR (DIAL), and differential-reflectance LIDAR (DIRL); biosensors and biomimetic sensors; and microelectromechanical systems (MEMS). Researchers in chemical, mechanical, nuclear, and electrical engineering, bioengineering, chemistry, spectroscopy, applied physics, and optics should be involved in these efforts.

• Perform case studies of actual IED construction and events todetermine whether and how resource control might be implemented,with the eventual goal of developing the ability to model theconnection between resources and the IED threat chain.

The availability of resources helps to determine the type, number, and effectiveness of IED construction; the ease or danger of manufacture and deployment; the lethality achieved; and the potential for detection and countermeasures. Key questions to be answered using case studies include these:

What energetic materials, initiators, triggering devices, and other materials were used, how were they obtained, and how was the IED delivered?

Why were some tactics, materials, and devices used in particular conflicts and contexts but not others?

and what methods can be used to diminish the threats (such as tracking, control, substitution, and adulteration)?

How does the availability of explosive precursors vary geographically?

Process and chemical engineers, explosives chemists, researchers who study historical and current terrorism, researchers in international studies, and operations researchers can make valuable contributions to answering those questions. The integration of that research in a way that recognizes the interplay of resources, human behavior, and context will be invaluable. Interactions between the researchers and customs officials, persons with expertise in tracking and resource management, and persons in manufacturing and professional organizations are recommended.

Attacks in London, Madrid, Bali, Oklahoma City and other places indicate that improvised explosive devices (IEDs) are among the weapons of choice of terrorists throughout the world. Scientists and engineers have developed various technologies that have been used to counter individual IED attacks, but events in Iraq and elsewhere indicate that the effectiveness of IEDs as weapons of asymmetric warfare remains. The Office of Naval Research has asked The National Research Council to examine the current state of knowledge and practice in the prevention, detection, and mitigation of the effects of IEDs and make recommendations for avenues of research toward the goal of making these devices an ineffective tool of asymmetric warfare. The book includes recommendations such as identifying the most important and most vulnerable elements in the chain of events leading up to an IED attack, determining how resources can be controlled in order to prevent the construction of IEDs, new analytical methods and data modeling to predict the ever-changing behavior of insurgents/terrorists, a deeper understanding of social divisions in societies, enhanced capabilities for persistent surveillance, and improved IED detection capabilities.

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